Friday, September 24, 2010

afferent feedback and the sense of ownership

In the involuntary action, there is the sense of ownership but there is not the sense of agency.

In this case, proprioceptive, kinesthetic and visual informations tells me that I am moving. The awareness of involuntary movement derives from afferent sensory feedback. But there are no efferent motor commands. This means that the sense of ownership is based on the sensory feedback.

The experiments of rubber hand illusion shows that it is enough with sensory feedback in order to create the sense of agency. The participants start to feel that the rubber hand belongs to himself/herself by being stroked synchronously on the real hand.

Friday, September 17, 2010


Annual Convention of Japanese Psychological Association is going to be held next week.

Japanese Psychological Association
74th Annual Convention
September 20-22, Osaka University, Osaka, JP

I am now preparing the poster which I will present on 21st in the morning. My poster is titled;

"Distinction between body schema and body image: A phenomenological account"
Shogo Tanaka (Tokai University)

I will review the classical work of Henry Head's body schema and Paul Schilder's body image, and then discuss the distinction between them, mainly based on Shaun Gallagher's work. I also add some original considerations.

Wednesday, September 15, 2010

Body Image and Body Schema, again

As I wrote here before, the term 'body image' and 'body schema' are often used indiscriminatingly or confusingly. But it is important to clarify the difference.

Body schema is the system of sensory-motor capacities which functions without awareness when we control the movement or adjust the posture. Body image is the complex images of perceptions, thoughts, emotions, memories pertaining to one's own body.

In my view, there are at least three differences between body schema and body image.

<1. Objectivity>
Body image is a kind of image which can be represented in the mind. It is the intentional object for the consciousness; we perceive, think and feel our own body. Body schema coordinates body parts toward an action pre-consciously and we can never be aware of its function.

<2. Person>
The body usually comes to one's senses as one's own body, not as other's. We perceive the body as something belonging to ourselves. This body is always perceived as 'my' body, not yours nor his/hers. In contrast, the function of body schema is anonymous, although it makes the person 'I' through its activity.

<3. Spatiality>
Body schema is not represented consciously. It is only lived from 'within'. Body image is the image of one's own body, which is perceived or looked from the 'outside'. To build such images, we need to borrow virtually the other person's viewpoint. Body schema is 'here' but body image is represented 'there'.

Tuesday, September 14, 2010

The 'minimal' self

Shaun Gallagher states that it is possible to simplify various notions of the self into two categories; the 'minimal self' and the 'narrative self'.
[Gallagher, S. (2000). Philosophical conceptions of the self: implications for cognitive science. in Trends in Cognitive Sciences. 4(1).]

Narrative self is the coherent self that is constituted with a past and a future in the various stories that we and others tell about ourselves. It is a kind of ordinary self that we experience in our daily lives.

The minimal self is a self which is composed of minimal factors; all of the unessential features are stripped away. It is the consciousness of oneself as an immediate subject of experience, unextended in time. It is the 'I' who is experiencing 'now-here'.

The minimal self has the two aspects; the sense of agency and the sense of ownership. The ownership is the sense that it is my body that is moving, and the agency is the sense that I am the initiator or source of the action. They are indistinguishable in the normal experience of willed action. We have both senses at the same time.

But in the case of involuntary action (e.g. someone moved my hand), it is possible to distinguish between them. I have the sense that I am the one who is moving, but I don't have the sense that I am controlling the movement. That is, I have the sense of ownership but I don't have the sense of agency.

It would be interesting to research the impairments, alterations or lesions of these two basic senses in various body awareness disturbances; phantom limbs, asomatognosia, anosognosia, depersonalization, hemiplegia, etc. It will bring a light to the relation between the body and the self.